Refers to where you behave responsibly during all of the progression through the various stages of intimacy, taking appropriate measures to protect both of you against undesirable things like infection or "accidental" pregnancy.
The best ways to "cover all the bases" with a new romantic partner are:
First base (i.e., hugging, holding hands, foot/back-rubs, etc.): Taking deeply-cleansing showers beforehand, brushing teeth, trimming hair and nails, etc.
Second base (i.e., kissing, close snuggling, sharing non-intimate full-body massages while wearing just a bathing suit or undies, etc.): Taking all steps described in "first base", plus using breath-fresheners, antiperspirants, soothing and/or aromatic oils, etc.
Third base (i.e., French kissing, naked cuddling, intimate massages, sleeping together, etc.): Taking all steps described in "first base" and "second base", plus having easy access to a warm/cold shower at all times, keeping the bedroom a comfy temperature, etc.
Fourth base (i.e., handjobs/blowjobs, "going all the way", etc.): Taking all steps described in first three "bases", plus having plenty of condoms and/or personal lubricant handy, keeping tissues and damp wash-cloths within easy reach to clean up "messy" aftermaths, having changes of sheets and pillowcases to put on the bed if necessary, etc.
First base (i.e., hugging, holding hands, foot/back-rubs, etc.): Taking deeply-cleansing showers beforehand, brushing teeth, trimming hair and nails, etc.
Second base (i.e., kissing, close snuggling, sharing non-intimate full-body massages while wearing just a bathing suit or undies, etc.): Taking all steps described in "first base", plus using breath-fresheners, antiperspirants, soothing and/or aromatic oils, etc.
Third base (i.e., French kissing, naked cuddling, intimate massages, sleeping together, etc.): Taking all steps described in "first base" and "second base", plus having easy access to a warm/cold shower at all times, keeping the bedroom a comfy temperature, etc.
Fourth base (i.e., handjobs/blowjobs, "going all the way", etc.): Taking all steps described in first three "bases", plus having plenty of condoms and/or personal lubricant handy, keeping tissues and damp wash-cloths within easy reach to clean up "messy" aftermaths, having changes of sheets and pillowcases to put on the bed if necessary, etc.
by QuacksO November 6, 2021
Get the cover all the basesmug. by @bre_Greg<3 February 7, 2022
Get the 27th basemug. 
what are the bases
1st . making out
2nd. feeling below waist
3rd. hand job/fingering
4th. (blow job)
5th. all the way
1st . making out
2nd. feeling below waist
3rd. hand job/fingering
4th. (blow job)
5th. all the way
jim: what are the bases?
john : you know don't you
jim: no, wait how far did you and lilly go yesterday
john: 3rd
john : you know don't you
jim: no, wait how far did you and lilly go yesterday
john: 3rd
by webegettinglitupinhere October 29, 2018
Get the basesmug. Opposite of "baseless" -- in reference to reports by the media that the public are entertaining "baseless" (conspiratorial) claims in an attempt to cover them up.
News Outlet: "...the baseless conspiracy that Epstein didn't kill himself."
Commenter 1: "Epstein was murdered."
Commenter 2: "Based."
Commenter 1: "Epstein was murdered."
Commenter 2: "Based."
by Vaginus Goochis Penicularis June 30, 2022
Get the Basedmug. Dude 1: if women can choose to have an abortion, men shouldn't have to pay child support because it was the woman's choice to carry the child to term
Dude 2: based
Dude 2: based
by okokaybro June 26, 2022
Get the basedmug. by Barboner September 23, 2017
Get the 6th basemug.