Is “Foci” a Scrabble word?
Yes
FOCI
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Foci
/ˈfəʊ.kaɪ/
noun
1.A point at which reflected or refracted rays of light converge.
“The heat of sunlight at the focus of a magnifying glass can easily set dry leaves on fire.”
2.A point of a conic at which rays reflected from a curve or surface converge.
3.The fact of the convergence of light on the photographic medium.
“Unfortunately, the license plate is out of focus in this image.”