Also see definition of "Alleluia" in Word Study
Study Dictionary
Alleluia
praise the Lord
Alleluia [EBD]
the Greek form (Rev. 19:1, 3, 4, 6) of the Hebrew Hallelujah = Praise ye Jehovah, which begins or ends several of the psalms (106, 111, 112, 113, etc.).
ALLELUIA [SMITH]
so written in (Revelation 19:6) foll., or more properly HALLELUJAH, praise ye Jehovah , as it is found in the margin of (Psalms 104:35; 105:45; 106; 111:1; 112:1; 113:1) comp. Psal 113:9; 115:18; 116:19, 117:2 The literal meaning of "hallelujah" sufficiently indicates the character of the Psalms in which it occurs as hymns of praise and thanksgiving.Also see definition of "Alleluia" in Word Study