Inboard

In´board`

a. & adv.	1.	(Naut.) Inside the line of a vessel's bulwarks or hull; the opposite of outboard; as, an inboard engine; an inboard cargo; haul the boom inboard.
	2.	(Mech.) From without inward; toward the inside; as, the inboard stroke of a steam engine piston, the inward or return stroke.

Adj.

inboard - located within the hull or nearest the midline of a vessel or aircraft; "the inboard flaps on the wing"

Antonyms:

outboard - located away from the midline of a vessel or aircraft; "the outboard section of a wing"; "outboard rigging"