When advancing one trips on the dewlap, retreating one stumbles on the tail.
Tips
history
疐 is famous from the 《诗经·豳风·狼跋》 — 狼跋其胡,载疐其尾 ('the wolf treads on his dewlap and trips on his tail'), a poetic image of being stuck between two impossibilities. The chengyu 跋前疐后 preserves the phrase as 'caught in a dilemma'.
register
Archaic — definitions follow classical attestation only. Outside the Shijing quotation and its set-phrase descendants the character is unused. Modern Chinese says 绊倒 (trip and fall) or 踉跄 (stagger).
Components
ideograph
疐zhì
to stumble
Compound ideograph. Top 口 over an inverted body element shows a figure caught with head pitched forward. Indexed under Kangxi #102 田 by graphic-shape tradition; the radical isn't transparently semantic in the modern form.
Filed under radical 疋 (pǐ, #103) by convention. 疋 is not a separate component in 疐, so no strokes are highlighted.