weak, frail
弱 centers on lack of strength or resilience: being physically weak, frail, or easily overcome.
弱 is composed of two 弓 (bows) with decorative or weakening strokes (冫), suggesting bows that are limp or lacking tension, hence weakness.
Two bows 弓弓 with extra strokes between them look like they've lost their snap. Imagine two limp bows that can't shoot arrows—they're weak and frail.
For ジャク, picture a weak jack-in-the-box that can barely pop up: jack -> ジャク, and its spring is too frail to work.
weak; frail; delicate; tender; unskilled; weak (wine)
a little less than; a little under; slightly fewer than
weak point; weakness; shortcoming; defect; flaw; sore spot; tender spot
weak; frail; fragile
to weaken; to grow weak; to wane; to decline (of one's health)
weak constitution; weak body
weak person; the weak; vulnerable person; disadvantaged person
(a) weakness; shortcoming; failing; sore point
coward; weakling; scaredy cat; wimp; sissy
to abate; to weaken; to be emaciated; to be dejected; to be perplexed
weakness; debility; breakdown; prostration
poor; meagre; meager; feeble; scanty; shabby; insubstantial
timid; weak-kneed; fainthearted
weakness
weak (constitution); sickly; feeble; in poor health
strength and weakness; (degree of) strength
feeble complaint; whine
to weaken
weak; feeble; delicate; frail; helpless
feebleness; weakness; imbecility
weak attitude
feebleness; weakness
twenty years of age
diminished capacity; diminished responsibility; legally unaccountable (e.g. due to mental illness, drugs, alcohol, etc.)
feeble-mindedness; intellectual disability