goniometer
Concise Oxford English Dictionary © 2008 Oxford University Press:
goniometer /ˌgəʊnɪˈɒmɪtə/
▶noun an instrument for the precise measurement of angles, especially the angles between the faces of crystals.
– derivatives
goniometric adjective,
goniometrical adjective,
goniometry noun.
goniometric adjective,
goniometrical adjective,
goniometry noun.
– origin C18: from Fr. goniomètre, from Gk gōnia ‘angle’ + Fr. -mètre ‘(instrument) measuring’.
'goniometer' also found in these Oxford entries:

