It can mean a lot of things. It can mean that the defense wants the state to provide the name and address of a witness (maybe a confidential informant) or possibly what a particular witness has to do with a case. It may also mean that the defense wants the sate to provide certain documents, pictures, or reports it believes the state has but has not given up.
It most likely means that your friend's attorney is trying to get more evidence from the state attorney or another party. This is sometimes a necessary aspect of criminal defense.
A motion to compel in a state criminal case usually concerns one side of the case trying to get the other side to do something required by law. For example, a motion to compel discovery or a motion to compel the identity of an informant.
Likely discovery related. Often times (unfortunate and unbelievable as it may sound) the state is a little lax/lazy on handing over information. The lawyer is likely addressing that.
Please be advised that nothing in this posting is meant to supplement the advice of an attorney and The Law Office of Robert J. Lee, P.A. and/or Robert J. Lee has not undertaken any professional responsibility with regard to your case unless otherwise agreed. RJL is licensed to practice law in FL and MA, but no other jurisdictions. Nothing stated herein should be implied as legal advice.