An attempt by men/boys to help women/girls and provide information they believe that the women/girls need. Usually, the intent it to be helpful, not condescending; however, the effect is condescending. As a result, a great deal of controversy and anger exists; as with many -isms, it is the effect and not the intent that results in the definition. In addition, with many -isms, those guilty of mansplaining react with anger, derision, and ridicule rather than considering it a teachable moment.
Male runner at the start line of a trail race, observing a woman drinking from a water bottle: "You know, you should be careful the amount of water you drink, so that you don't suffer from hyponatremia. It's a very serious problem that can lead to death."

Female runner: "Um, thanks for the mansplain. I have a degree in exercise science, so if you'd like more information on that subject, I can help you out. "
by lynnsdaughter August 17, 2016
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verb, informal
(For a man) to feel a need to explain something basic in great detail to a woman, in a condescending manner, based purely on the expectation that she is unfamiliar with the subject matter because she is female.

Occasionally done as a well meaning, but ill aimed attempt to pick someone up.
This guy saw me changing my oil in my driveway. He came over and asked, "Do you need some help, there, sweetheart?" I said, "Thanks, but I've got it covered. I kind of like it, actually." He stayed to mansplain the entire process, step by step, AS I was doing it. Then he gave me his number and said to call him if I ever have any questions.
by Jassess September 20, 2017
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When a man explains something to a woman, uninvited, about a topic she is either equally qualified or more qualified to talk on.

A male doctor explaining something to a female patient, for example, would not be mansplaining.

Examples: The guy who tried to tell Margaret Atwood about "The Handmaid's Tale", the guy who told Katie Mack, who has a PHD in Astrophysics, to "learn some science" because he thought climate change was a hoax, the man who tried to correct a woman about how to pronounce her own name correctly, an Englishman correcting a Welsh woman on her Welsh pronunciation.

See also Dunning-Kruger effect.
Look at this idiot trying to mansplain periods to women... he thinks women only have nine periods a year... wait 'til you hear his lecture on how to insert a tampon correctly!
by Jorgs August 2, 2019
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When someone "explains" something to another person about a topic they are already familiar with/understand. This is typically done in a condescending manner under the pretense that the speaker knows more about the topic than who they are speaking to, i.e. they are subordinate.
1) Explaining the rules of poker to a poker dealer
2)Repeating a point back to someone in your own way, even if they just said the same thing
3)Telling a person that you know more about something because of blank, even though they are a professional/have a degree in the field that you do not have

Sidenote: it is okay to know a lot about a topic and make this known in conversation, but assuming that you know more than someone else, not accepting if you are wrong, not accepting that they may simply be more knowledgeable, and/or doing so in a condescending manner means that you are mansplaining.

Note: this definition and examples were built together by both a man and a woman
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When a man explains something to a woman in a patronizing tone as if the woman is too emotional and illogical to understand.
"She got all pissed at me for no reason!" cried Ira, "Accusing me of mansplaining."
Aziz shook his head. "Women! Right?"
by Babydoll75 March 7, 2019
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When unsolicited advice or direction is given to a woman by a man in a condescending manner. The reasons typically being, the man does not believe the woman is capable of completing the task independently and must need guidance.
"You're not doing that how I would do it so I'm going to bother you with my directions and opinions even though I am in no way a superior and you did not ask for clarification. There is no way you are capable of doing this by yourself and must be ignorant so you have to rely on my constant guidance."

"uh, I think I got it.. thanks."
Mansplaining
by tybkylie December 14, 2018
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A blend of man and explain. When a person explains something to another about a subject on which the latter is more knowledgeable. Usually the word describes a conversation in which, due to sexist bias, a man automatically assumes he is more knowledgeable than the woman he is talking to.
Man: "Let me explain you something-"
Woman: "Dude. I have a PhD in this subject. I'm pretty sure I know more about it than you do."
Man: "Yeah,you have a PhD, but hear me out-"
Woman: "Do you realise you are mansplaining right now?"
by theTransMusician July 4, 2018
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