Verb. From Turkish.
“To have your legs give way and then collapse”
Caution should be taken with this word as its translation can vary a little. Within certain contexts, it can mean the above (including a more defined mention of the legs ‘opening’ before collapse?!) but it can also mean ‘to squat,’ or even ‘to be astonished.’ Perhaps the latter of these is figurative? I’m not sure; my Turkish is atrocious!