We found 3 dictionaries that define the word under one's hat:

General (3 matching dictionaries)

1. under one's hat: Merriam-Webster
2. under one's hat: Wiktionary
3. under one's hat, under ones hat: Dictionary.com

Phrases: keep something under ones hat, more... ▸ Words similar to under one's hat ▸ Usage examples for under one's hat ▸ Idioms related to under one's hat ▸ Wikipedia articles (New!) ▸ Words that often appear near under one's hat ▸ Rhymes of under one's hat ▸ Invented words related to under one's hat