Compound words like SNOWMAN etc, are obvious compound words in Modern English, as both words that make up the compound word exist as words in Modern English.
However, words like SHEPHERD aren't words made up of 2 actual English words (SHEP isn't a word in Modern English), but was originally a compound word in Old English (the word originates from Middle English schepherde, from Old English sċēaphierde, a compound of sċēap (“sheep”) and hierde (“herdsman”)) or a compound word in another language like Latin for example. In these instances, would these words (words that seem like compound words but aren't made up of 2 actual English words) be defined as "compound words" in Modern English?
Secondly, is https://en.wiktionary.org/wiki/Category:English_compound_words a reliable/accurate source for identifying whether a specific word is a compound word?
EDITED FOR CLARIFICATION: I'm sorry for the vagueness of the question, as I'm asking as layman who's confused about the conditions for a word to be defined as a compound word. For clarification, I'm referring only to closed compound words (just a single word) and more specifically words being spelled/written out. And my interpretation of compound words matches what Edwin Ashworth has quoted, 'Compounding derives a new word by joining two morphemes that would each usually be free morphemes.' and I define a free morpheme as 'a morpheme that can stand alone as its own word'. My issue with SHEP in SHEPHERD is that SHEP isn't a word in the dictionary, which is why I am uncertain as to whether SHEPHERD meets the requirement to be a compound word.
My questions are: (Q1): is SHEPHERD a compound word?
(Q2): does a (closed) compound word have to be made up of 2 or more english words that exist in the dictionary (SNOW+MAN = SNOWMAN)? (whereas shep is typically not a word in the dictionary, thus I do not think of it as a free morpheme)
(Q3): if the answer to (Q1) is yes, did SHEPHERD inherit its status as a compound word due to it evolving from the Old English "sċēaphierde" which is a compound word formed by sċēap and hierde?