to put it mildly Definition

mild
adj milder, mildest

1. Gentle in temperament or behaviour.

Thesaurus: gentle, kind, meek, amiable, serene, easygoing, moderate; soothing, smooth, mellow, delicate; Antonym: fierce, harsh.
2. Not sharp or strong in flavour or effect.
3. Not great or severe.
4. Said of climate, etc: not characterized by extremes; rather warm.

Thesaurus: temperate, summery, pacific, tropical, balmy, clement, clear, sunny, warm, calm, fair; Antonym: rough, cold, stormy.

noun

1. Dark beer less flavoured with hops than bitter beer.

Form: mild ale (also)

Derivative: mildly
adverb

Derivative: mildness
noun

Idiom: to put it mildly

To understate the case.

Etymology: Anglo-Saxon milde.