Also samhita originally merely meant a collection, from dhA: to place, bestow, make, cause, perform, an old word represented in the Vedas quite often and with cognates in languages from Greek to Germanic, an English cognate being `do'; with the prefix saM: with, together, another very old word with cognates all across, some English relations possibly being some or same. This original meaning of `put together' is obvious in its uses in the Rg veda. It also meant, some in only slightly later usages, joined together as in a grammatical euphonic conjunction (usually called saMdhi, another word from the same root); the general concept of relatedness; and also the `force' that holds the universe together; but the meaning most common today as you point out arises from the slight coloration already visible in the texts (prAtishAkhya) explaining the Rgveda: the placing together of an uninterrupted series of words. In this sense, it forms parts of the names of many works, like the famous treatise of astronomy called bRhatsaMhita, literally the huge collection.
Of course, today it means the real continuous part of the vedas with their proper phonetic elements (the concept of, possibly tonal, stress disappeared except for the metric part of the vedas being referred to here; and the `word' like the Greek concept of logos being important in the religion, this was an important division) as contrasted to the other parts of the vedic literature.
That said, I was not aware of samhita meaning precisely a stanza of the holy books from Hindu mythology in any language that I know (Sanskrit and a few modern North Indian languages to a limited degree): the meaning I am familiar with, and as indicated above, is the entire collections of such stanzas. However, the modern languages of India have borrowed heavily from Sanskrit and moulded them to novel uses, and, also, meanings slowly drift along the ages, so with a meaning of the specificity you gave, a reference to a particular linguistic dictionary, or at least the language, would help.