What was the name of that tool again?

Quickly find the name of any command line tool.

We type commands in the terminal every day. But if you forgot the exact name of a tool, what do you do?

Use man -k followed by part of the tool you want. It searches in the command name itself or in the description. You are guaranteed to find the tool you were looking for.
For example, to find all backup commands:

$ man -k backup

btrfs-select-super (8) - overwrite primary superblock with a backup copy

idevicebackup (1) - Create or restore backup for devices.

idevicebackup2 (1) - Create or restore backups for devices running iOS 4 or...

luckybackup (8) - a powerful, fast and reliable backup & sync tool

luckybackup-pkexec (8) - a powerful, fast and reliable backup & sync tool

mysqlpump (1) - a database backup program

...

To play?

$ man -k game

gamemoded (8) - optimizes system performance on demand

intro (6) - introduction to games