The Spanish verb reír, meaning 'to laugh', comes directly from the Latin verb ridere, which had the same meaning. The evolution from Latin ridere to Spanish reír shows typical sound changes that occurred as Latin developed into Spanish, including the loss of the intervocalic 'd' and the shift of the ending.

Some related Spanish words include risa (laughter), risueño (cheerful, smiling), and sonrisa (smile). All these words share the same Latin root ridere and form a family of words related to laughter and cheerfulness in Spanish.

While English 'laugh' is not related to reír, we can find the Latin root rid- in English words like 'ridiculous' and 'deride'. 'Ridiculous' literally means 'worthy of laughter', while 'deride' means 'to laugh at' or 'to mock'. These English words preserve the connection to laughter from the original Latin meaning.