Kolla upp vilket ord som helst, t.ex. twoosh:
 
1.
Like a hard on, it comes about when some thing is arousing, but not enough to induce a full erection.
While watching two average women make out, Jim noticed that he was sporting a half on.
av Harry T 14 augusti 2007
 
2.
A semi-erect penis. (See: Semi, Chub) Fifty percent of a Hard-On. A "bulge in the pants," as it were.
I often get a half-on while leering at females on the subway.
av Time4SumAksion 6 september 2005
 
3.
When a mans dick gets bigger but not hard enough yet to not be bendable either with starting to get a boner or starting to go down.
Damn that guy has a huge dick

Nah he just has a half-on
av Its_Fucking_T0m 14 juni 2011