膨ふくらす

膨らす · godan verb (-su)

Meanings

godan verb (-su), transitive verb

rare term

Rare transitive verb meaning to cause something to swell or expand. In modern Japanese, 膨らます is far more common for this meaning.

膨ふくらます
膨らます is the standard modern transitive form meaning 'to inflate' or 'to expand'. 膨らす is a rare variant with the same meaning, mostly found in older texts.
膨ふくらむ
膨らむ is the intransitive counterpart meaning 'to swell' or 'to expand' (something swells by itself). 膨らす is the transitive form (someone expands something).

膨ふくらすUsage17%
Standard kanji spelling for this rare transitive verb; the kanji 膨 is associated with swelling or expanding.
ふくらすUsage83%
Kana spelling may be used for clarity or when the kanji is not needed.
脹ふくらす
Alternate kanji spelling; 脹 is less common and typically used for bodily swelling.

Derived from the intransitive verb 膨らむ (ふくらむ) by changing the ending to the transitive suffix す. The kanji 膨 is used for swelling or expanding.