This is the 4332nd most frequent German word.
floh
"Floh" means "flea" in English.
In this sentence, 'Floh' refers to an actual flea, related to the idiomatic expression 'einen Floh ins Ohr setzen' implying causing a persistent thought or annoyance.
Ich hatte einen Floh im Ohr und konnte nicht schlafen.
I had a flea in my ear and couldn't sleep.
Here, 'Floh' is simply the noun for the insect flea, showing its literal usage.
Der Floh sprang über das Blatt.
The flea jumped over the leaf.
Here, 'floh' is used as the past verb form of 'fliehen', meaning 'to flee'.