This is the 2161st most frequent Chinese word.
感冒
"感冒" means "cold" (as in the illness).
In this sentence, '感冒' is used as a verb meaning 'to catch a cold'.
昨天我觉得不舒服,可能是感冒了。
Yesterday I felt unwell, maybe I caught a cold.
Here, '感冒' acts as a noun referring to the condition of having a cold.
感冒的时候要注意休息,多喝水。
When you have a cold, you should rest and drink more water.
In this case, '感冒' is used as a verb indicating the act of catching a cold.