Katherine Heigl has had more than enough of the F-word (the gay slur), and thinks her co-star Isaiah Washington should quit using it, forever.

Once again defending her "best friend in the whole world," T.R. Knight, in an interview with 'EXTRA,' Heigl says that the "Grey's Anatomy" dirty laundry needs to be dealt with "in-house" and that it's "discouraging." While she says she's hopeful that a proper detente can be reached, Heigl is "not cool" with Washington's hurtful comments.

Neither, for that matter, is ABC, which said today that it was "greatly dismayed" by Washington's outburst.