[adj] securely fixed in place; "the post was still firm after being hit by the car" [adj] not capable of movement or of being moved
fast, firm, fixed, immotile, immovable, immoveable, nonmotile, stabile, stiff, unmovable
mobile
abiding, adamant, adamantine, at a standstill, at anchor, changeless, constant, contemplative, continuing, dead-still, do-nothing, dormant, durable, enduring, firm, fixed, frozen, idle, immotile, immotive, immovable, immutable, inactive, inert, inflexible