From Longman Dictionary of Contemporary Englishwhat the heckwhat the heck spoken informalUNIMPORTANTused to say that you will do something even though you really should not do it It’s rather expensive, but what the heck. → heck
Examples from the Corpus
what the heck• And what the heck did it all mean, anyway?• Hey, what the heck, another big hit from Alomar, and here comes Palmeiro.• I just want to know what the heck happened.• I was like what the heck does that mean?• Oh, what the heck - TrueEffects is great fun.• So what the heck, folks.• Martinique, she thought, what the heck, why not give the nude beach a try?• Parents of later learners cringe and begin to wonder what the heck is going on. 