Fancier naming

df |> summarize(across(a:c,
    list(
      mean = \(x) mean(x, na.rm = TRUE), 
      median = \(x) median(x, na.rm = TRUE)
    ),
    .names = "{.fn}_of_{.col}"
))

## # A tibble: 1 × 6
##   mean_of_a median_of_a mean_of_b median_of_b mean_of_c median_of_c
##       <dbl>       <dbl>     <dbl>       <dbl>     <dbl>       <dbl>
## 1    -0.111      -0.261     0.191     -0.0207     0.275       0.387