Boyd’s Bible Dictionary:
(through). [GATE.]
Concise Bible Dictionary:
Besides the common use of the door as the means of entrance into a house, and of enclosing those within when shut, it is used in scripture symbolically for the way of entrance into blessing. The Lord said, “I am the door: by me if any man enter in, he shall be saved.” Salvation is only by Him. He also said that as the true Shepherd He entered into the sheepfold by the door, that is, though Son of God, He entered as obedient by God’s appointed means, being circumcised, presented in the temple, and baptized (John 10:1-9). God opened “the door of faith” to the Gentiles by Paul and Barnabas (Acts 14:27). Opportunities for service are called opened doors (1 Cor. 16:9; 2 Cor. 2:12; Col. 4:3; Rev. 3:8).
When the church is represented as in a Laodicean state the Lord is outside knocking for admission at the door of the assembly, so that the individual may hear, with a promise of blessing to those who open to Him (Rev. 3:20).
Doors in the East are usually made of wood; but in the deserted cities of Bashan doors are found cut out of stone, with a projection top and bottom which served as pivots on which the door turned.
Strong’s Dictionary of Greek Words:
Meaning:
apparently a primary word (compare "door"); a portal or entrance (the opening or the closure, literally or figuratively)