Make out sloppily in the library? Crossword Clue

 The answer to the crossword clue "Make out sloppily in the library?" is ARCS. 6D.

The clue is a bit of a double entendre, as it can be interpreted both literally and figuratively. Literally, it could refer to two people kissing and hugging in the library in a way that is messy and uninhibited. Figuratively, it could refer to two people engaging in a passionate intellectual discussion in the library.

The answer, ARCS, is a pun on the word "arc", which can refer to both a curve and a passionate embrace. The "sloppily" part of the clue is also reflected in the fact that ARCS is a relatively short word, suggesting that the kissing and hugging is not very graceful or controlled.

I hope this helps! Let me know if you have any other questions.