From kauchaomai; a boast (properly, the object; by implication, the act) in a good or a bad sense -- boasting, (whereof) to glory (of), glorying, rejoice(-ing).
see GREEK kauchaomai
1. that of which one glories or can glory, matter or ground of glorying: Romans 4:2; 1 Corinthians 9:15; 2 Corinthians 1:14; Philippians 2:16; τό καύχημα ἔχειν εἰς ἑαυτόν μόνον, his glorying confined to himself (R. V. in regard of himself alone), Galatians 6:4; τό καύχημα τῆς ἐλπίδος, the matter for glorying which hope gives, i. e. the hope, of which we glory, Hebrews 3:6.
2. As γέννημα, δίωγμα, θέλημα. ἴαμα, κήρυγμα (2 Timothy 4:17), κλαῦμα, πλήρωμα, φρόνημα, etc., are used for γέννησις, δίωξις, θέλησις, κτλ. (cf. Ellicott on Philippians 4:6), so also (which H. A. W. Meyer persists in denying (as respects the New Testament (see his note on Romans 4:2); so Ellicott and Lightfoot on Galatians 6:4; Lünem. on Heb. as above)) is καύχημα used for καύχησις (Pindar Isthm. 5, 65 (cf. Meyer on Philippians 1:26 note; on the apparent use of nouns in μά in an active sense see Lightfoot on Colossians, p. 257f)), a glorying, boasting: 1 Corinthians 5:6; Philippians 1:26; ὑπέρ τίνος (see καυχάομαι, under the end), 2 Corinthians 5:12; 2 Corinthians 9:3.