Try something like this:
Macaulay2, version 1.19.1
with packages: ConwayPolynomials, Elimination, IntegralClosure, InverseSystems,
LLLBases, MinimalPrimes, PrimaryDecomposition, ReesAlgebra,
Saturation, TangentCone
i1 : R = QQ[x_1]
o1 = R
o1 : PolynomialRing
i2 : x_1
o2 = x
1
o2 : R
i3 : baseName x_1
o3 = x
1
o3 : IndexedVariable
i4 : peek oo
o4 = IndexedVariable{x, 1}
i5 : (baseName x_1)#1
o5 = 1