A shortened form of a written word or phrase used in place of the whole . Some say that the distinction between an acronym and an abbreviation is that an abbreviation becomes an acronym if it is pronounced as if it were a word. So NASA, WYSIWYG and CORBA are acronyms while IBM and HTTP are not. SCSI on the other hand is usually pronounced "scuzzy", so would be an acronym.?I pronounce IBM as ib-bum, and HTTP as hit-tup, must I still call them abbreviations? The confusion is apparently caused by different uses of the word "word": is every consecutive sequence of alphabetic characters a word, or does it have to be a pronouncable sequence of syllables? For an abbreviation to be an acronym it needs to be a) an initialism (to be made up of the heads of its component words: for example the initial letters) and b) it should be treatable as a word. SNAFU satisfies both of these criteria, and so is an acronym. 'Amt' fails to be an acronym for 'Amount' on both counts. Acronym: a word (as NATO, radar, or snafu) formed from the initial letter or letters of each of the successive parts or major parts of a compound term. Some say that the distinction between an acronym and an abbreviation is that an abbreviation becomes an acronym if it is pronounced as if it were a word. So NASA, WYSIWYG and CORBA are acronyms while IBM and HTTP are not. SCSI on the other hand is usually pronounced "scuzzy", so would be an acronym. I pronounce IBM as ib-bum, and HTTP as hit-tup, must I still call them abbreviations? The confusion is apparently caused by different uses of the word "word": is every consecutive sequence of alphabetic characters a word, or does it have to be a pronouncable sequence of syllables? For an abbreviation to be an acronym it needs to be a) an initialism (to be made up of the heads of its component words: for example the initial letters) and b) it should be treatable as a word. SNAFU satisfies both of these criteria, and so is an acronym. 'Amt' fails to be an acronym for 'Amount' on both counts