jack·knife

noun

/ˈdʒæknaɪf/

(plural jackknives

/ˈdʒæknaɪvz/

)

verb

/ˈdʒæknaɪf/

[intransitive]

Verb Forms

present simple I / you / we / they jackknife	/ˈdʒæknaɪf/ /ˈdʒæknaɪf/
he / she / it jackknifes	/ˈdʒæknaɪfs/ /ˈdʒæknaɪfs/
past simple jackknifed	/ˈdʒæknaɪft/ /ˈdʒæknaɪft/
past participle jackknifed	/ˈdʒæknaɪft/ /ˈdʒæknaɪft/
-ing form jackknifing	/ˈdʒæknaɪfɪŋ/ /ˈdʒæknaɪfɪŋ/

to form a V-shape. For example if a lorry that is in two parts jackknifes, the driver loses control and the back part moves towards the front part.弯成 V 字形（如铰接货车失控时的弯折）Topics Transport by car or lorryc2
Oxford Collocations Dictionary
Jackknife is used with these nouns as the subject:
lorry