What is the effect of the the symbol "" on the meanings of the words in the Quran, and does not elongating the letter beneath it change the meaning?

The tilde sign () indicates an elongation (madd) that exceeds the natural madd. It is used in the necessary madd (madd lazim) like "al-Tāammah" (extended for 6 counts), and in the connected madd (madd muttasil) like "sawā’un ‘alaynā" (extended for 4-6 counts). It is also used in writing as a substitute for a hamza followed by an alif, such as (āmana, ādhānunā, Ādam). This sign does not alter the meaning of the words; rather, it is an indication of the elongations that the Prophet used in his recitation.