also: むしメガネ
A convex lens used to enlarge the appearance of objects. Common in daily life, science, and hobbies.
My grandfather reads the small print in the newspaper with a magnifying glass.
lowest-ranked sumo wrestler
Sumo slang for a wrestler in the lowest division (jonokuchi). The term likens the wrestler to an insect under a magnifying glass, implying small size or insignificance.
He is still a wrestler of the lowest rank, but he trains hard every day.