Fetching details from the dictionary...

sweat; perspiration
moisture; condensation
gulp; oops
「汗」 has another reading with different meanings.
運動して汗をたくさんかきました。
I sweated a lot from exercising.
冷たいビールのグラスに汗が浮いていた。
Beads of condensation had formed on the glass of cold beer.
緊張で冷や汗が出てきます。
I broke out in a cold sweat from nervousness.