  We present systematic measurements of azimuthal anisotropy for strange and
multi-strange hadrons ($K^{0}_{s}$, $\Lambda$, $\Xi$, and $\Omega$) and
$\phi$-mesons at mid-rapidity ($|y| <$ 1.0) in collisions of U+U nuclei at
$\sqrt{s_{NN}} = 193$ GeV, recorded by the STAR detector at the Relativistic
Heavy Ion Collider (RHIC). Transverse momentum ($p_{\text{T}}$) dependence of
flow coefficients ($v_{2}$, $v_{3}$, and $v_{4}$) is presented for minimum bias
collisions and three different centrality intervals. The results are obtained
using the $\eta$ sub-event plane method. These measurements are compared with
the published results from Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV.
Number of Constituent Quark (NCQ) scaling of the measured flow coefficients in
U+U collisions is discussed. We also present the ratio of $v_{n}$ scaled by the
participant eccentricity ($\varepsilon_{n}\left\lbrace 2 \right\rbrace$) to
explore system size dependence and collectivity in U+U collisions. The
magnitude of $v_{2}/\varepsilon_{2}$ is found to be smaller in U+U collisions
than that in central Au+Au collisions contradicting naive eccentricity scaling.
Furthermore, the ratios between various flow harmonics ($v_{3}/v_{2}^{3/2}$,
$v_{4}/v_{2}^{4/2}$) are studied as they are sensitive to the properties of the
medium and mechanism of hadronization. The measured flow coefficients and the
ratios between different flow harmonics are compared with hydrodynamic and
transport model calculations.
