doff a hat

桐野 夏生の "Grotesque" を読んでいます。Yurikoを殺した容疑者の供述からの引用です。

So why did I kill her? you ask. I don't even understand it myself. Perhaps it was because she pulled the wig off her head as easily as if she were doffing a hat. The hair that emerged from between the wig was light brown flecked with white. Miss Hirata was some kind of foreigner who looked nothing like my Mei-kun!

"doffing a hat" は帽子を脱ぐ意味のようですが、辞書で確認します。

・Oxford English Dictionary: Take off or raise (one's hat) as a greeting or token of respect.: ‘the manager doffed his hat to her’
・Collins Dictionary: to take off or lift (one's hat) in salutation: Somehow he managed to compose himself sufficiently to doff his hat to her and to say most civilly, `My lady, how nice to see you.
・Cambridge English Dictionary: to remove your hat, usually to show respect: She also doffed the masculine top hat or bowler and donned a tiny feather-trimmed hat.
挨拶として帽子を持ち上げる意味もあるのですね。上記最後の辞書の例文で分かるように "doff" は "don"　の対語ですね。