Green’s Dictionary of Slang

1. (orig. US campus) a general excl. of approval or enthusiasm, absolutely! exactly! really!

1982		Frank Zappa ‘Valley Girl’ 🎵 Like, OH MY GOD! (Valley Girl) Like – TOTALLY (Valley Girl).
1996		Eble Campus Sl. Sept.
2000		P. Howard Miseducation of Ross O’Carroll-Kelly (2004) 20: And Aoife’s there, ‘Totally. It’s like, oh my God! hello?’.
2023		J. Jackson Pineapple Street 141: ‘[E]ven when they have more that they could realistically need in a lifetime, it doesn’t feel like they have enough.’ ‘Totally,’ Darley agreed.

2. as adv.

2005		J. Salazar Legion of the Lost 202: ‘I do hope you have a totally fun weekend’.
2014		J. Bacharach Bend of World 16: Lauren Sara and I are going. I can totally get you a ticket, though.