Encumbrance, n.
Etymology: [Cf. OF. encombrance. Cf. Incumbrance.]
1. That which encumbers; a burden which impedes action, or renders it difficult and laborious; a clog; an impediment. See Incumbrance.
2. (Law)
Same as Incumbrance.
Syn. -- Burden; clog; impediment; check; hindrance.
Shades of meaning
Fernald has no entry of its own for encumbrance; he lists it under impediment, load.
Where he writes about it:
That which rests upon one as a burden is an encumbrance. — from impediment
An encumbrance is always what one carries with him; an obstacle or an obstruction is always without. — from impediment
To a marching soldier the steepness of a mountain path is a difficulty, loose stones are impediments, a fence is an obstruction, a cliff or a boulder across the way is an obstacle; a knapsack is an encumbrance. — from impediment