Ustadh Nouman Ali Khan talks about and emphasizes on the meaning of the word - Qawlan Sadeedah [The Right Words].
The power of words is the quintessential power bestowed upon man and is a gift from Allah. When we speak, we communicate with Allah and hence, we should be vigilant on how we use them in our daily lives.
The word Saddah means filling a hole or a gap. Regarding speech, Sadd “سد” in Arabic means to fill in something. Our conversations should be such that it doesn’t create any further problems, if some already exist, rather fill that void. one should be thoughtful of his tone/voice/statements.
‘Sud’ also means a dam that separates and mountain (a reference to Surah Yasin and Kahf) it encourages us to speak with knowledge or don’t speak anything. We should only speak if we have something positive to contribute to a conversation. We should also take care to speak straight/clearly so listeners can tell where it began and where it ended, unlike tangled cables or ropes where no one can tell where starts and where it ends. Say what you want others to hear, thus, leaving no room for ambiguity. Lastly, we should speak with “purpose”.