We have many versions of semantic holism in the philosophy of language and the philosophy of thought.
Take Donald Davidson.
Davidson believed that the
“account of the truth-conditions for any one sentence is systematically related to the account of the truth-conditions for a whole range of other sentences”.
(We can now ask: How large must this range of other sentences be?)
We can clarify Davidson’s semantic holism in terms of the systematicity of a concept-expression and its possession. As Michael Luntley puts it:
“The axiom governing any single concept expression does not itself specify the meaning of the expression; it does so only in the context of an overall theory that employs that axiom in a systematic manner to compute the meaning of whole sentences in which the concept expression figures.” (1999)
The starting point of Davidson’s theory is Frege’s Context Principle in which the meaning of an expression is determined by its context and place within a truth-valued sentence. Davidson extends Frege’s Context Principle to include other sentences in which the said expression occurs. It's from this group of sentences (large or small) that we can compute the expression’s meaning within the context of an overall theory.
We also have a well-known statement from Davidson on meaning-holism that's sometimes taken as a criticism of holism; though, at other times, simply taken as an explanation of the phenomenon.
In his paper, ‘Truth and Meaning’, Davidson writes:
“If sentences depend for their meaning on their structure, and we understand the meaning of each item in the structure only as an abstraction from the totality of sentences in which it features, then we can give the meaning of any sentence (or word) only by giving the meaning of every sentence (and word) in the language.” (1967)
This may not mean that the individual speaker (or thinker) need understand (or know) every word and sentence in the language at the moment of his understanding: only that in effect the meaning of a word or sentence is ultimately determined by - and depends upon - the entire language (regardless of the complete understanding of the individual speaker or thinker).
For example, the possible moves in a game of chess are finite though very large. It needn't be the case that the individual chess-player understands (or knows) all the possible moves in the game of chess in order to make a single move (or understand the rules of chess generally).
The same with definitions.
There will come a time that the indefinite regress of definitions (or definitions of definitions) will come to end when the original definiendum comes back on the scene. However, it doesn't follow that the individual speaker (or thinker) need go through this indefinite regress in order to use (or understand) the word under definition - even if an indefinite regress is entailed by the original definition.
The individual speaker (or thinker) needs to begin somewhere; just as the epistemologist won't attempt to justify all his premises in an argument of justification. Even the semantic sceptic needs Wittgenstein’s ‘hinges’ to turn on in order to get his sceptical show on the road.
Davidson, Donald, 'Truth and Meaning' (1967)Luntley, Michael, Contemporary Philosophy of Thought: Truth, World, Content (1999).