Answer:
lexicon
Step-by-step explanation:
Lexicon -
The term refers to the vocabulary knowledge of a person.
As , Ron loves to read , he keep on reading and as soon as he get any new word he searches the meaning and thereby increases his lexicon.
The more we read or write new words and meaning , the better he learn and remembers the meaning of a particular word , and increases our lexicon.
Hence, from the question,
The correct term for the given question is lexicon.