Two senses share this reading: a land-area unit (still seen in 公顷, 'hectare') and 'a brief moment', as in 顷刻 (顷刻, 'in an instant'). The modern everyday word is 公顷 for hectare.
页 is the 'head' radical (its original sense, not 'page'). With the tilted figure beside it, the character first meant an inclined head, later borrowed for the area unit and the 'brief moment' sense.
匕 here depicts a person with the head tilted. Combined with 页 (页, head), the original picture is a head leaning to one side — the 'tilt' sense that the qīng reading still carries.
