sesquiquadrate /ˌsɛskwɪˈkwɒdɹət/adjective 1noun 1forms 1 adjective1 •Of or noting the aspect or position of any two celestial bodies separated by 135°. noun1 •A sesquiquadrate aspect or position; an angle of 135°: (a square [90°] + a semisquare [45°]; abbrv. Ses). formssesquiquadrates