In a tart manner; sharply; with acidity; usually figurative with asperity of tone. In quot. 1600, ‘with sourness of aspect’ (Johnson).

Disagreeably, unpleasantly; crossly, gloomily, unfavourably. Chiefly in to look sour.

In a sour, peevish, or disagreeable manner. With intransitive verbs, esp. to look.

In a crabbed manner: crossly, ill-temperedly; sourly, morosely; with rugged intricacy.

With bitterness of feeling.

In an acrimonious manner; with bitterness or severity.

In early use: with a sour, bitter, or astringent flavour. Now chiefly: in a sharp or cutting manner; acerbically. Cf. acerb, adj. 1.

somewhat tartly.

(In quots. figurative).