Wiktionary
geekish
a. Like a geek; having the traits of a geek.
Usage examples of "geekish".
Not quite as geekish as his friend Jeff had been before the Ring of Fire deposited their hometown in seventeenth-century Germany, but still something of an oddball in rural West Virginia.
He was a fairly young-looking, geekish kind of guy, not much personality-wise, but he sure knew his job.
Joss accepted with a geekish grin, now comfortably changing his personality with each stranger he met.