When a girl estimates how large her strapon needs to be for her girlfriend.
Usually involves one female partner testing a wide range of dildos on the other female partner.
When one partner is strapolating the other, the latter partner is said to be being "strapolated" by the other partner (present tense).
Once the female partner being tested on cannot take a larger dildo without being in excruciating pain, she is said to be "strapolated" (as the correct strapon length & width has been determined). This being the past tense.
When one partner is strapolating the other, she is said to be undergoing, "strapolation".
Strapolation must be undertook with extreme care, as an overly large dildo used as a strapon can cause serious harm to the partner who is having the dildo inserted into her. When such occurs, this is known as, "overstrapolation", as the partner has over-estimated how much of a dildo her partner can take. "Understrapolation", occurs when the partner strapolates a smaller dildo than is required, thus leaving the partner dissatisfied.