  AE Aquarii (AE Aqr) is a cataclysmic binary hosting one of the fastest
rotating (P$_{\rm spin}$ = 33.08 s) white dwarfs known. Based on seven years of
Fermi Large Area Telescope (LAT) Pass 8 data, we report on a deep search for
gamma-ray emission from AE Aqr. Using X-ray observations from ASCA, XMM-Newton,
Chandra, Swift, Suzaku, and NuSTAR, spanning 20 years, we substantially extend
and improve the spin ephemeris of AE Aqr. Using this ephemeris, we searched for
gamma-ray pulsations at the spin period of the white dwarf. No gamma-ray
pulsations were detected above 3 $\sigma$ significance. Neither phase-averaged
gamma-ray emission nor gamma-ray variability of AE Aquarii is detected by
Fermi-LAT. We impose the most restrictive upper limit to the gamma-ray flux
from AE Aqr to date: $1.3\times 10^{-12}$ erg cm$^{-2}$ s$^{-1}$ in the 100
MeV-300 GeV energy range, providing constraints on models.
