['ni:plʌs'ʌltrә]
n.
最远点, 至高点

[ noun ]
the state of being without a flaw or defect
<noun.state>

Ne plus ultra \Ne plus ul"tra\ [L., no further; ne no, not +
plus more + ultra beyond.]
1. The uttermost point to which one can go or attain; hence,
the summit of achievement; the highest point or degree;
the acme.
[Webster 1913 Suppl.]

2. A prohibition against proceeding further; an insuperable
obstacle or limiting condition. [Obs. or R.]
[Webster 1913 Suppl.]