This word is often translated “gentle” but is not quite the same as praus gentleness. It carries the idea of being reasonable.
HELPS Word-studies 1933
epieikḗs (an adjective, derived from 1909 /epí, “on, fitting” and eikos, “equitable, fair”; also see the noun-form, 1932 /epieíkeia, “equity-justice”) – properly, equitable; “gentle” in the sense of truly fair by relaxing overly strict standards in order to keep the “spirit of the law.”
1933 /epieikḗs (“justice beyond ordinary justice”) builds on the real intent (purpose) of what is really at stake (note the epi, “upon”) – and hence, is true equity that appropriately fulfills the spirit (not just the letter) of the law.
This is applicable to men.
Let your reasonableness [epieikḗs] be known to everyone. Phil. 4:5
An overseer must be…not a drunkard, not violent but gentle [epieikḗs], not quarrelsome, not a lover of money. 1 Tim. 3:3
But the wisdom from above is first pure, then peaceable, gentle [epieikḗs]… Jam. 3:17