Answer: firths

AnswerCrossword Clue
FIRTHSScottish inlets
FIRTHSClyde, Forth and others
FIRTHSNarrow arms of the sea
FIRTHSEstuaries
FIRTHSLong, narrow estuaries
firthslong, narrow indentation of the seacoast
firthsFIRTH, an inlet of the sea, also FRITH