-ling

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. One connected with: worldling.
2. n. One having a specified quality: underling.
3. n. One that is young, small, or inferior: duckling.
4. n. In a specified direction, manner, or condition: darkling.

Wiktionary

1. n. A diminutive modifier of nouns having either the physical sense of "a younger, smaller or inferior version of what is denoted by the original noun", or the derived sense indicating possession of or connection with a quality, which may having the sense of "a follower or resident of what is denoted by the stem form".
2. n. as an adverb In the manner or direction indicated by the main stem (object.)

GNU Webster's 1913

1. n. A noun suffix, commonly having a diminutive or a depreciatory force; as in duckling, gosling, hireling, fosterling, firstling, underling.
2. An adverbial suffix.