Narrow - Vine's Expository Dictionary of New Testament Words
Narrow[ A-1,Adjective,G4728, stenos ]
from a root sten---, seen in stenazo, to groan," stenagmos, "groaning" (Eng., "stenography," lit., "narrow writing"), is used figuratively in Matthew 7:13-Matthew 7:14, of the gate which provides the entrance to eternal life, "narrow" because it runs counter to natural inclinations, and "the way" is similarly characterized; so in Luke 13:24 (where the more intensive word agonizomai, "strive," is used); RV, "narrow" (AV, "strait") in each place. Cp. stenochoreo, "to be straitened," and stenochoria, "narrowness, anguish, distress."
[ B-1,Verb,G2346, thlibo ]
"to press," is translated "narrow" in Matthew 7:14, AV, lit., "narrowed" (RV, "straitened;" the verb is in the perfect participle, Passive Voice), i.e., hemmed in, like a mountain gorge; the way is rendered "narrow" by the Divine conditions, which make it impossible for any to enter who think the entrance depends upon self-merit, or who still incline towards sin, or desire to continue in evil. See AFFLICT, No. 4.