“way.” This is the Hebrew word derek (#01870 דֶּרֶךְ), referring to a road, not just a small path or “way,” but we felt like “way” read much better here than “road.”
“fill.” This is one of the wonderful “obscure expressions” and “riddles” of the wise (cp. Prov. 1:6). The Hebrew word translated “satisfied” here in Proverbs 1:31 is saba (#07646 שָׂבַע), which refers to eating or drinking enough to be satisfied. However, it also has the negative meaning of eating to the point of being overfull and then getting sick or getting to the point the food is revolting, and in that sense, it is used for being repaid for what one has done, thus they will “get what their ways deserve” (NRSV). The context determines which meaning saba has, but in this verse, both meanings apply. The two contrasting meanings of saba account for the different translations, those which read “satisfied” or “filled,” (ASV; KJV; NASB; NIV; Rotherham), and those which try to say “filled” but in a negative way (“overfilled” CJB; “glutted” HCSB; “glutted” NAB; “stuffed full” NET).
This is a good example of the figure of speech amphibologia (double entendre), where a word has two (or more) different meanings and both are true. The people who ignore the counsel and reproof of Wisdom are generally “satisfied” with the choice they have made. For example, if they choose to ignore Wisdom and steal and rob to get rich, they may be very satisfied with their wealth, or if they choose to lie and defame others to get political position and power, they may be very satisfied with that. But eventually, even if it takes until Judgment Day, those fools will be “stuffed full” to the point of revulsion with the results of their own plans. This verse is similar to Proverbs 14:14. It is a consistent theme through Scripture that evil people bring evil upon themselves (see commentary on Prov. 1:18).
[See figure of speech “amphibologia.”]