The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix II
Semitic Roots
ENTRY:
dl.
DEFINITION:
Common Semitic noun *dalt-, door (*-t-, feminine suffix). 1.daleth, from Hebrew dlet, from Phoenician *dalt, door, fourth letter of the Phoenician alphabet. 2.delta, deltoid, from Greek delta, from Phoenician *dalt (see above) or from a dialectal variant *dilt.