QSO noun 2verb 1forms 3 noun2 •(old-fashioned) A radio-quiet quasar. •Initialism of quasi-stellar object (“a quasar”). verb1 •(slang) To communicate (with) by means of amateur radio.The basic award is issued when 500 countries have been successfully QSOed on the three bands. — 1993 formsQSOed · QSOing · QSOs
