# tmux ls
keepMe: 1 windows (created Wed Jun 24 14:20:15 2015) [171x41]
otherSession: 1 windows (created Wed Jun 24 14:22:01 2015) [171x41]
3: 1 windows (created Wed Jun 24 14:23:28 2015) [171x41]
(assuming here that you're on keepMe session)
# tmux kill-session -t otherSession
-or-
# tmux kill-session -t 3
tmux 关闭session
3 min read