[moving thread to Photoshop forum]
No, photoshop 7 will not work on mac os x 10.9.4 mavericks.
Photoshop 7 for mac os requires a PowerPC processor and your mac has an intel processor.
Also. sounds like you have the windows version, which wouldn't work on the mac side anyway.
Any photoshop version of cs3 and newer should work on your mac, but i would suggest not trying to find a used version, but instead go with photoshop cs6 (buy) or photoshop cc 2014 (subscribe)
because there is a very good chance used versions or ones from ebay that say new but never used are pirated versions.