We speak of a thing as blameless when it is free from blame, or the just imputation of fault; as, a blameless life or character. The last three words apply only to the general character, while blameless may be used in reverence to particular points; as, in this transaction he was wholly blameless.

Webster's Revised Unabridged Dictionary (1913)

Example sentences

innocent From this evidence it follows that he is innocent.
righteous A good Muslim strives to be good and righteous.
shameless That shameless smile says it all; he knows what he is.

Popularity over time

Word	1850 → 2019	Trend
blameless		rising
innocent		rising
righteous		rising
sinless		rising
guiltless		steady
shameless		rising

Use in printed books, per decade from 1850 to 2019.

By length

4 letters: just¹, pure¹
5 letters: clear¹, clean¹, pyore
7 letters: perfect², sinless
8 letters: innocent³, virtuous³, spotless²
9 letters: righteous², stainless², shameless², faultless, unsullied³, guiltless², undefiled, unspotted
10 letters: impeccable⁴, inculpable
11 letters: unblemished³, offenseless, offenceless
13 letters: unimpeachable⁵
14 letters: irreproachable
15 letters: irreprehensible

The small number after each word is its number of syllables (perfect² = 2 syllables).