spi·rom·e·ter 
(spī-rŏmĭ-tər)
(spī-rŏmĭ-tər)n.
An instrument for measuring the volume of air entering and leaving the lungs.
spi′ro·metric (-rə-mĕtrĭk) adj.
spi·rome·try n.
- infill
- infiltrate
- infiltration
- infiltrative
- infiltrator
- infin.
- in fine
- in fine (or good or high)feather
- in fine (or good or high) feather
- in fine or high feather
- infinite
- infinitely
- infiniteness
- infinitesimal
- infinitesimal calculus
- infinitesimally
- infinitival
- infinitive
- infinitude
- infinity
- infirm
- infirmary
- infirmity
- infirmly
- in fits and starts