I use the term "outside back" to refer generically to any back who plays "outside" the center-backs -- i.e., to include both fullbacks and wingbacks, etc. as well as right versus left. I thought that was an appropriate term in the context of talking about the various positions that Dom could play other than CB.
That said, it makes me feel better to know that even you Brits sometimes get confused about how the lingo has changed over time. The potential confusion is doubled for me because of differences between the lingo used in American "soccer" versus "football" in other countries.
I played "soccer" as a kid, and as I recall the lingo at that time was very much influenced by American football. We played on a "field," not a "pitch," which was bordered by "sidelines" rather than "touch lines," and when we didn't have "games" (not "matches") we went to "practice" (not "training"). After that, my primary experience in watching soccer/football for most of my adult life has been watching the USWNT on television, with American announcers and commentators. It is only within the last few years that I've broadened my horizons and become such a big fan of the WSL (and the Lionesses). I'm still learning.
My childhood experience in playing football was more than 50 years ago, so I don't remember a lot of details, but there's one thing I do remember that might make some of your brains to explode. I was on a couple of teams in which my position was designated as "center half" -- but that referred to what we would now call a central "midfielder." As I recall, all of the defensive backs at the time were called "fullbacks," and midfielders were called "halfbacks" -- following what was then an important distinction in American football at that time that no longer exists.
