lock [sth] down, lock down [sth]vtr phrasal sepphrasal verb, transitive, separable: Verb with adverb(s) or preposition(s), having special meaning, divisible--for example, "call off" [=cancel], "call the game off," "call off the game."
(make secure)
把…固定住
把…锁住
Please securely lock down the skis on the roof rack.