look out for number one
To act in one's own interests; to act in a manner advantageous primarily to oneself.
Meaning adapted from Wiktionary, available under CC BY-SA 4.0.
“He always looks out for number one in every situation.”
“In this competitive industry, you must look out for number one if you want to succeed.”
“She realized that her colleagues were only looking out for number one, so she stopped sharing her best ideas with them.”
Attested since the 1830s at the latest, the phrase is a compound of *look out for* and *number one*, the latter functioning as a substitute for oneself.
- 01
as best one can
In the best possible way, given one's circumstances and abilities.
- 02
as far as one knows
To the best of one's knowledge, as far as someone knows or possible information to be gathered about the topic, subject, aspect, or situation.
- 03
back to square one
Located back at the start, as after a dead end or failure.
- 04
beat as one
To share the same feelings.
- 05
become one flesh
To join together in marriage; to develop a unifying bond as a result of marrying.
- 06
bite off more than one can chew
To try to do too much; to take on or attempt more than one is capable of doing.
- 07
bite the big one
To perform poorly; to fail.
- 08
bite the hand that feeds one
To cause harm to a benefactor (especially one that one is dependent on, thus with the idea that this behaviour is self-damaging).
Last updated August 10, 2026