Searching the terminal

Click the magnifying glass in the tab bar (Search in terminal) to open the search bar, and type. Matches are highlighted in the visible output and the scrollback.

Shortcut
⌘G	next match
⇧⌘G	previous match
Esc	close search

How far back you can search depends on the scrollback: Settings → Terminal → Scrollback sets how many lines each session keeps.