Question

what is the meaning of the word discern as used in the passage? as the sun began to set, the island castaway was barely able to discern a ship on the horizon. did that mean that someone onboard the ship might be able to notice him, too? he jumped to his feet and frantically waved his arms, yelling, \over here! over here!\ to detect to reach to search for

Explanation:

In the context, the castaway could barely see the ship on the horizon. "To detect" means to notice or discover something, which fits the context as the castaway was able to notice the ship. "To reach" implies getting to a place and "to search for" implies actively looking for something, neither of which fit as well as "to detect".

Answer:

to detect