To find out or observe (someone or something, especially if not easy to see) by spying or looking; to catch sight of; to see; to spot.
To see (someone or something) without foreplanning or unexpectedly.
To notice, observe, learn, or understand, especially something otherwise overlooked.
To adopt a practice in which others already engage.
To continue or build upon (for example, a task, analysis, or narrative), beginning from a point at which someone has previously stopped.