look up any word, like plopping:
 
7.
a fat girl dressed in slutty clothes
Wow, she is a sea-donkey
by john smith December 04, 2003
 
1.
A human female resemblant of a sea cow(aka manatee), but with a face far less smooth or attractive, being more like that of a donkey or other equine familiar. It is a miracle of nature that these women are land-dwelling, rather than living in the ocean, considering the frame-stress resultant of their girth would be far better supported in an aquatic environment.
Damn! Look at that sea donkey eat! Keep her away from children or someone could lose a finger!
by The Miracle Man June 17, 2003
 
2.
A extremely large and fat woman who fronts like she is hot and sexy. Related closely to the "beached whale."
If you go to the fill in station to drink you have to be careful because the seadonkeys are out in full force.
by Kendizzle June 09, 2005
 
3.
An extremely unattractive female who is usually found in dim areas and has lots of lumps. Very much resembles a donkey who just crawled out of the sea.
Girls always look better in dim light. You show up at her house the next day to pick her up and next thing you know a dang ol' sea donkey done jumped in yo' car.
by Thebattles June 12, 2011
 
4.
A girl who is unattractive due to face, weight, or personality who is notoriously difficult to get rid of. A girl who doesn't get the obvious hints that they are not wanted.
Man: Gee, you seem pretty tired, I will call you a cab.

Seadonkey: Oh, I'm not too tired. I can stay.

or

Seadonkey: Thats ok, I will just crash here.
by Leah SG September 08, 2006
 
5.
a girl so ugly and hideous that normal words cannot describe her so you must resort to referring to her in the terms of manatee or some water elephant type creatures
i saw john last night heading home from the club with that seadonkey. man he must have been wasted!
by spc diggins October 15, 2007
 
6.
unattractive female, sea horses arent good looking, imagine what a sea donkey would look like!
"damn jake, how come your mums so hot? my mums a sea donkey"
by cellardoor4130 May 31, 2005