The katakana syllable フ (fu). Its equivalent in hiragana is ふ (fu). It is the twenty-eighth syllable in the gojūon order; its position is ハ行ウ段 (ha-gyō u-dan, “row ha, section u”).

the boiling point / (figuratively) criterion of stimulus to change expression.

incompetent / incapable, inefficient / impossible

incompetence / incapability, inefficiency / impossibility

the emperor's seal

(obsolete) cloth woven of hemp or ramie, similar to linen

inconvenient

anxiety; uneasiness / unrest

(card games) hanafuda, literally “flower cards”, a card game of Japanese origin

taking up a new post