Medieval coin/token ?

[bridgemanneil]

all,
I recently found what I believe could be a medieval coin while metal detecting in a cornfield in Castletown, Celbridge (Ireland), and I’m hoping to get some opinions on it.
The piece is quite small — smaller and thinner than a modern 2 cent coin. It appears worn, but I can make out what looks like a cross on one side. There are also some pellet-like markings, and possibly a letter (maybe an “A”) beneath them, though it’s not very clear.
The shape isn’t perfectly round, which made me wonder if it could be clipped, broken from a larger coin, or possibly even a token rather than an official issue. The metal doesn’t seem obviously copper — I initially thought it might be silver, but I’m not certain.
I’ve attached photos of both sides. Unfortunately, the detail is quite faint, but I’d really appreciate any thoughts on:
What type of coin this might be
Whether it looks medieval (and if so, what period)
Or if it could be something else entirely (token, foreign, etc.)
Thanks in advance for any help!