Definition of measure one's length in English:

measure one's length

phrase

dated
  • (of a person) fall flat on the ground.

    ‘he uttered a groan and measured his length in the dust’
    • ‘Oreste stumbles, recovers, stumbles again - and measures his length on the ground in a dead faint.’
    topple over, tumble over, keel over, fall down, fall over, go head over heels, go end over end, fall headlong, go headlong, collapse, fall in a heap, take a spill, pitch forward
    get into debt, get into arrears, default, be in the red, be late, be overdue