Terminology in data science and computing is messy. I came across a StackOverflow suggested edit that wanted to rewrite all OP's dataframe to data frame.
- The R source dictionary includes dataframe, not data frame, yet a
grep shows this is not the convention.

- The
data.frame function includes a dot that suggests a space
- Github fails to give conclusive result (dataframe & data frame), but makes it more complex. Pythonistas prefer dataframe. Microsoft disagrees!
- On StackOverlow, data frame gives 76,079 results (
[r] tag) and 120,469 without, dataframe has 66,709 ([r] tag) and 333,282 without.
- Oxford English & Cambridge dictionaries see and hear no evil - neither are present
I'm inclined to say dataframe, similar to database, where emphasis is not placed on frame, but rather on data.
What is your to-go-to spelling, and why?