誠実 /sei ji tsu/ means sincere in its main sense, like 'true, genuine'. 忠実忠実しい /ma me ma me shii/ means sincere in sense of 'diligent, hardworking'.
Some close words would be:
素直 /su na o/ 'honest, straightforward'.
満腔 /man kou/ 'heartfelt, with all one's heart'.
実らしい /ji chi ra shii/ 'sincere-looking, honest in manners'.
You may say 'seijitsu.'
The Sanskrit word for sincere is "ईमान्दार" (īmāndār).
The superlative degree of word sincere can be most sincere ,or sincerest according to its use in the sentence.
The root word for "sincerely" is "sincere," which comes from the Latin word "sincerus," meaning "pure" or "genuine."
The superlative degree of word sincere can be most sincere ,or sincerest according to its use in the sentence.
The base word of sincerely is sincere.
A sincere person is always respected for his sincerity. This is the sincere approach to make a sentence with the word 'sincere'.he was sincere in his efforts to please
The word you are looking for is likely "affable." This term describes someone who is warm, sincere, and friendly in their interactions with others.
Comparative: more sincere Superlative: most sincere
The way you have it spelled in your question is as good as any - it's not really a word. Sincere is a word who's comparative and superlative are : more sincere, most sincere.
She was sincere and honest.
The word 'sincere' is not a noun, sincere is an adjective, a word to describe a noun. The noun form for sincere is sincereness, an abstract noun. Another abstract noun form is sincerity.