The Collaborative International Dictionary of English v.0.48:
Trim \Trim\, a. [Compar. Trimmer; superl. Trimmest.] [See
Trim, v. t.]
Fitly adjusted; being in good order., or made ready for
service or use; firm; compact; snug; neat; fair; as, the ship
is trim, or trim built; everything about the man is trim; a
person is trim when his body is well shaped and firm; his
dress is trim when it fits closely to his body, and appears
tight and snug; a man or a soldier is trim when he stands
With comely carriage of her countenance trim.
So deemed I till I viewed their trim array
Of boats last night. --Trench.