look up any word, like ebola-head:
 
1.
Erect penis; see: boner
Long Dong Silver could never get a real hard on, because his penis was so long.
by Jorge December 06, 2002
 
2.
An erect penis.
see also boner,stiffy etc.
'When Bob saw Jenny by the pool in her bikini he got a big Hard-On'
'When my dog licks my balls i get a Hard-On'
by Disturbed1 November 23, 2003
 
3.
Man's most magnificently majestic manifestation of masculinity, and the one potentially most exciting to a woman. It looks like a rocket ready to be launched, and has the same turbulent thrusting force and energy.
It signals to a woman that a guy is ready and able to have sex with her and eager to do so, which, if she finds him attractive, tends to kindle her interest. For that reason, it is a serious though common mistake for a guy to be embarrassed or self-conscious when he has an erection.
Freshman year, after pulling an all-nighter, I stripped and got in bed, only to wake a half hour later with an urgent need to piss. I got up without waking enough to know I was naked, much less that I had wood, and walked down the hall to the bathroom. Only as I walked past the open door of another room down the hall and saw a woman grad student staring at me with wide eyes did I look down and see I was sporting the most giant hard-on I'd ever seen in my life. Afterwards, she kidded a male grad student we were both friends with that I had a better body than he did. He replied, "You've seen more of it than I have."
by Adam Phillips August 18, 2006
 
4.
the act of the penis getting hard/stimulated/an erection
the boy announces to the class that he has a hardon.
by Holmes December 04, 2002
 
5.
An erection of the penile variety. Can i say erection on the internet?
Oi, cowboy from the village people! Did the leather man give you a hard on?
by Tom Brownlee July 29, 2003
 
6.
Slang word for the fast-food chain Hardee's.
Do you want to go to Hardee's, Barfy's, Pizza Slut, or Taco Smell?
by andy1 May 14, 2005
 
7.
an erected penis (boner, stiffy, chubby)
When she comes over to me, i get a hard on and it dont stop till tomorrow one of these days im gonna cum, IN MAH PANTS
by KawaiiAnime November 22, 2003