1680s, "to melt, make liquid by heat" (transitive), back-formation from fusion. Intransitive sense, "to become liquid," attested from 1800. Figurative sense of "blend different things, blend or unite as if by melting together" is recorded by 1817. Intransitive figurative sense "become intermingled or blended" is by 1873. Related: Fused; fusing.
"leaning, reclining," 1705, from Latin recumbentem (nominative recumbens), present participle of recumbere "recline, lie down, lie down again;" of things, "to fall, sink down, settle down," from re- "back" (see re-) + -cumbere "to lie down" (related to cubare "lie down;" see cubicle). Related: Recumbency (1640s); recumbence (1670s). A verb, recumb, has been attempted in English occasionally since 1670s.
"barricade defense made of felled trees with the branches angled outward," 1766, from French abatis, literally "things thrown down," from Old French abateiz "a casting down; slaughter, carnage" (12c.), from abatre "to beat down, throw down" (see abate).