ˈ ̷ ̷ ̷ ̷ˌfōt noun
also iso·phot -ˌfät
( -s )
Etymology: International Scientific Vocabulary is- + -phote, -phot (from Greek phōt-, phōs light) — more at fancy
: a line or surface on a chart forming the locus of points of equal illumination or light intensity from a given source