Wiktionary
alt. 1 (context not comparable US English) Situated or happening outside the boundaries of a military base. 2 (context not comparable baseball of a baserunner English) Positioned somewhere between the bases, and hence vulnerable to being caught out. 3 (context comparable figuratively of a person English) mistaken; misguided; somewhat wrong in opinion or judgment. 4 (context comparable figuratively of an action, belief, idea, etc English) incorrect or inappropriate; not properly executed, envisioned, or understood. prep.phr. 1 (context not comparable US English) Situated or happening outside the boundaries of a military base. 2 (context not comparable baseball of a baserunner English) Positioned somewhere between the bases, and hence vulnerable to being caught out. 3 (context comparable figuratively of a person English) mistaken; misguided; somewhat wrong in opinion or judgment. 4 (context comparable figuratively of an action, belief, idea, etc English) incorrect or inappropriate; not properly executed, envisioned, or understood.
Usage examples of "off base".
Firelli's lab determined to find a way of placing a phone call off base.
Vedya asked, seeing her struggles to see through the crowd and indicating a pillar that rose from a low, squared-off base.
It would be worse, she thought, since many of them lived off base.