Upadhyayi, or upadhyaya, refers to one who teaches when approached (upetya adhiyate asmat). In the Manu-samhita it is said:
eka-desam tu vedasya vedaṅgany api va punah yo 'dhyapayati vrtty-artham upadhyayah sa ucyate
"One who teaches others a part of the Vedas or literatures supplementary to the Vedas may be called upadhyaya." Upadhyaya also refers to one who teaches art.