Not a real word. It's "at least". They're two different bloody words. The type of people who write 'atleast' are the same delinquents who write 'alot' 'abit' 'alittle' etc.
Synonyms for atleast
On this page, you will find 30 slang terms related to atleast. Some of the top words include: oxy moron, saadly, stupider, oxymoron, get your neck, and 25 more.