The word āhāva is irregularly formed when meaning 'a trough'.,
The word आहावः is irregularly formed from ह्वे by the prefix आ, then samprasarana, and the vriddhi of the vowel. Thus आ + ह्वे + अप् = आहु + अ = आहौ + अ = आहावः 'a trough near a well for watering cattle'. Otherwise आह्वायः 'calling'. Even in the word आहावः the sense of calling is understood. It is that place near a well, containing water, where cattle are called or invited to drink water.,