Oh, don't worry. I'm looking for my gu

Solution:

The sentence fragment is 'I'm looking for my gu'. The dropdown menu offers 'dirty', 'mess', and 'rubbish'. Considering the context of searching for something, and the options provided, 'gu' is likely a typo for 'gum'. Therefore, 'gum' is the word being looked for.

Answer: gum