looks like; appears like
Indicates that something appears or looks a certain way based on direct observation or impression.
そうだ is used when you make a judgment based on what you see, hear, or sense directly. It often translates as 'looks like' or 'seems'. For verbs, it expresses that something is about to happen or appears to be happening. For adjectives, it describes the appearance of a quality.
Be careful not to confuse this with the homophone そうだ meaning 'I heard that', which follows plain forms and is used for hearsay. The two are different grammar points with different attachments.
Also note that for い-adjectives like ない and いい, the stem changes: なさそうだ for ない, and よさそうだ for いい.