Raca

Strong’s Dictionary of Greek Words:

Number:
4469 (find all occurrences in KJV Bible)
Greek:
ῥακά
Transliteration:
rhaka
Phonic:
rhak-ah’
Meaning:
of Chaldee origin (compare 7386); O empty one, i.e. thou worthless (as a term of utter vilification)
KJV Usage:
Raca

Jackson’s Dictionary of Scripture Proper Names:

vain: empty

Potts’ Bible Proper Names:

Empty; a vain fellow; worthless:― a term of contempt and reproach, Matt. 5:22. {Vanus}