Could Sincere be the perfect name for your baby boy? The baby boy name Sincere is 7 letters long, and contains 3 vowel(s) and 4 consonant(s). Sincere is a baby boy name that starts with the letter S and ends in the letter E. The baby boy name Sincere has a popularity of 40% and is ranked 600 in the list of top 1000 most popular baby boy names. If Sincere isn't the ideal name for your baby boy then take a look here for some randomly generated names. Hopefully you'll find a more suitable first name for your baby boy than Sincere!