Very good topic MB Singh jeeo.
Indeed, there are many words in Gurbani that can't be translated in English. The first word, for some reason, that came into my mind is ਝੁੰਝਨੜਾ from the following Gurbani Pankiti:
ਰਣ ਝੁੰਝਨੜਾ ਗਾਉ ਸਖੀ ਹਰਿ ਏਕੁ ਧਿਆਵਹੁ ॥Whenever I read this Pankiti, it gives a very different feeling to the mind. It is extremely sweet and loving. The strange thing is that this Chhant was not completed and left with just 2 Pankitis. Guru Sahib alone knows the reasons for this. Another such Shabad that is not complete in Gurbani is that of Bhagat Soordaas and goes as follows:
ਛਾਡਿ ਮਨ ਹਰਿ ਬਿਮੁਖਨ ਕੋ ਸੰਗੁ ॥This Pankiti appears alone and the proceeding Shabad is that of Siri Guru Arjun Dev jee addressed to Bhagat Soordaas jee and explains the Pankiti of Bhagat jee. It is said that when Bhagat Soordaas got this Baani, he went into Samaadhi and could only say this much. What a great Hukam is stated in this Pankiti. The Pankiti clearly gives Hukam to give up company of those people who have turned away from Vaheguru i.e. are Bemukhs of Vaheguru.
Kulbir Singh