Meanings
Informal, euphemism for “hell”. An expression of strong agreement, enthusiasm or support
Examples
“Was it a good bargain?” “Heck, yeah! I paid only 10% of the list price” 
“È stato un buon affare?” “Altroché! L'ho pagato solo il 10% del prezzo di listino”“How was your job interview? Did it work out?” “Heck, yeah! I've been hired on the spot”
“È andato bene il colloquio di lavoro?” “Altroché! Mi hanno assunto sui due piedi”“Do you really think that my suggestion is a good one?” “Heck, yeah!”
“Pensi davvero che la mia sia una buona idea?” “Altroché!”Origin
Heck is a euphemism for the H… word, which stands for Hell. It is a harsh, profanity-based word; it is considered a curse word and can be offensive