tip his cap back

Ｆｌｏｗｅｒｓ ｆｏｒ Ａｌｇｅｒｎｏｎ主人公、Charlieは脳の手術後少しずつ知恵がついて来ているようでスペルの誤りも減ってきました。ベーカリーの仲間はCharlieにパン作りができるか試そうとしています。
The two men sit down at the long table, the tall Frank and the heavy Gimp shaping the dough for the rolls that have to be baked for the evening orders.
They work in silence for a while, and then Frank stops and tip his cap back. "Hey, Gimp, think Charlie could learn to bake rolls?"
この小説は主人公が知恵遅れのお陰でいわゆる難しい単語はほとんど出てきません。しかし簡単な単語でも私が知らない意味は幾らでもあります。上の文の "tip" もその例です。辞書のこの "tip" の意味を調べます。
・Macmillan Dictionary: to put something into a position that is at an angle instead of upright: The dog tipped her head to one side.: He tipped his chair back and looked at me.
・Collins Dictionary: to take off, raise, or touch one's hat in salutation
・Merriam-Webster's Online Dictionary: to raise and tilt forward in salute: tipped his hat
・Wiktionary: To briefly remove or tap one's hat as a gesture of greeting, deference, or respect.
簡単な単語でも色々な意味を持っているのですね。