One of the names of Śiva-Mahādeva (Siva-Mahadeva) mentioned in Śivasahasranāmastotra (Sivasahasranamastotra; The Hymn of Thousand Names of Siva). Here, the two names of Mahādeva, Āṣāḍa (Ashada) and Suṣāḍa(Sushada) have been mentioned together. Nīlakaṇṭha (Nilakantha), the commentator, has also provided annotations of these two names together. The term Āṣāḍa derives from the Sanskrit dhātu (dhatu; root-verb)  ‘Saḥ’, which means ‘to endure’. But in this case, the word is used as prayoyaka kriya (verb as agent), and so, it should mean ‘to make endure’. He is known as Āṣāḍa because he endows us with power to endure all sufferings, pains and odds —
Āṣāḍaḥ sāhayateḥ kartari niṣṭhā ā samantāt sarvaṁ sāhayati sahanaṁ karayatītyāṣāḍaḥ sarvasahanasāmarthyaprada ityarthaḥ.

In this sense, He is also known as Suṣāḍa. He makes all situations good and enjoyable to us — hence, this name.