Is it a medical condition to not able to recall the word in a language while having a conversation
The phenomenon you describe is known as tip-of-the-tongue phenomenon, where you know there is a word, and you feel it's "right on the tip of the tongue, but doesn't come out".

The phenomenon is normal and tends to worsen with age. Only in case it becomes so strong that it seriously interferes with daily life, it can be considered a medical condition (anomic aphasia) that may be indicative of damage to the brain, such as stroke, head trauma, dementia, or tumor.