I could have sworn that I have heard/read the word "steward" in a context similar to the following:
"His precise measurements of the motion of mercury, made over the course of eight consecutive years, made him a steward of science."
In the sentence above, it's clear that steward is taken to mean, roughly, "One who upholds core values". However, the word as per the Merriam-Webster dictionary is,
Steward [noun | stew·ard | \ˈstü-ərd, ˈstyü-; ˈst(y)u̇rd]
(1) a person and especially a man whose job is to serve meals and take care of passengers on a train, airplane, or ship
(2) someone who protects or is responsible for money, property, etc.
(3) a person whose job is to manage the land and property of another person
It seems like the definition I am thinking of can be thought of as a mild contortion/stretching of the standard definition. Can "steward" take on such a meaning that I have outlined in my example sentence, or am I gravely mistaken? Regardless of whether or not it is, could you give me words which match my hypothesized definition (i.e. words that mean "One who upholds core values")?