Is dancing forbidden for men?

There is no harm in men dancing on Eid or to show courage in war, as long as it is not taken as a profession or exceeds limits. As for dancing during remembrance (dhikr) and worship as an act of nearness to God, it is an innovated bid'ah (religious innovation) that is rejected, due to the Prophet's (peace be upon him) saying: "Whoever introduces into this matter of ours that which is not from it, it is rejected."