The old photograph radiated pathos, a quiet ache for lost time.
Here, the synonym of the word "pathos" is -

• Pathos [Uncountable Noun]
English Meaning: (in writing, speech and plays) The power of performance, description, etc. to make you feel sympathy or be sad.
Bangla Meaning: করুণ রস।

Synonyms: Emotion (আবেগময়), Sadness (ব্যাথা/বেদনা), Tragedy (বিয়োগান্তক), Poignancy (মর্মস্পর্শীতা), Desolation (নিরানন্দতা)।

Antonyms: Cheer (উদ্দীপনা), Happiness (খুশী), Joy (আনন্দ), Glee (উল্লাস), Softness (স্নিগ্ধতা)।

Example Sentence:
1. The scene was full of pathos.
2. Our knowledge of his tragic end adds an element of pathos to the story of his early success.

Source:
1. Cambridge Dictionary.
2. Accessible Dictionary by Bangla Academy.