Archived - Mac OS X: Terminal window is too small, or doesn't appear
Terminal is a utility for executing command line instructions in Mac OS X. If its window is very small and can't be resized (Mac OS X 10.3, 10.4), or does not appear at all when Terminal is opened (in Mac OS X 10.5) make sure the Monaco font is enabled.
Terminal needs Apple's Monaco font. If that font is disabled or missing, the Terminal window will be very small and unusable, or may not appear at all.
Use Font Book to enable Monaco in the All Fonts collection. If you'd previously picked a different custom font for Terminal windows, enable that font, or select a different font.